The present invention relates to a driving device for a model plane, particularly, to a rubber band driving device for a two-propeller model plane, in which the two propellers rotate in opposite directions at equal speed.
Model planes of various kinds are being developed in many a country the world over; and development on model planes driven by rubber band has a long lead, since such models are easy and quick to assemble, safe to use, involve a low cost, and have low requirements as to the environment for use. In addition, such model planes fly gracefully; they are, therefore, widely and much used for purposes of aeronautic education and scientific popularization. They also suit outdoor games and serve as children toys as well.
In recent years, rubber band driven model planes, particularly emulation planes, have been a big hit among the public. Nevertheless, the conventional rubber band driven emulation model planes are all of the single-propeller type, since the single-propeller device results in a simple transmission mechanism, and is easy to manufacture. It is, however, noted that in the past years it was still the two-propeller model that was most welcomed by the public and became marked in the history of model planes; and people have been eager to be provided with emulation model planes of this kind. In recollection of history, an example is the xe2x80x9cNo. 1 Flyerxe2x80x9d designed and test flown by the American Wright Brothers. That serves as a push for us to develop, as soon as possible, a rubber band driven two-propeller model plane.
Based on the above prior art, it is the object of the present invention to provide a rubber band driving device for a two-propeller emulation model plane, in which a single rubber band is used to drive two propellers to rotate at equal speed and in opposite directions, with a simple control switch and a rubber band winder suited for use with rubber bands of different powers. Another object of the present invention is to provide a rubber band driving device, reasonable in structure, simple to manufacture, and easy to maintain and repair, to be applied to various kinds of model planes. The driving device of the present invention comprises a power rubber band, a wooden skeletal bar, a rubber band winder, a rubber band locator, a power distributor, transmission bars, support bars, a left propeller gear box, a right propeller gear box, blades of the propellers, a propeller space locating bar, and a propelling direction adjuster; wherein the rubber band winder is connected to one end of the wooden skeletal bar, and on the wooden skeletal bar there are fitted a rubber band locator, a power distributor, and a propelling direction adjuster; said power rubber band being linked at one end to the rubber band winder, and to the power distributor at the other end. Two transmission bars and two support bars are connected, respectively, to the said power distributor, and further to the left and right propeller gear boxes. The propeller space locating bar is connected at both ends to the left and right propeller gear boxes, and form, together with the two support bars a triangular structure. Blades are fitted onto the left and right propellers.
In accordance with the present invention, in the preferred embodiment of the invention, there is provided a single rubber band driving device for an emulation model plane with two propellers. When a winding handle is inserted into a ratchet gearing box to wind up clockwise the said rubber band, the latter will store up power; and when a switch is pushed, by means of two drive screws, a driving torque will be transmitted from the rubber band to the gear boxes of both the right and the left propellers; and by means of different arrangement in the two gear boxes, the two propellers will rotate at equal speed but in opposite directions. As a switch is provided, unless it is pushed on, the dynamic power stored in the said rubber band will not be released.
The driving device for two-propeller model planes according to the present invention has the following advantages: 1) The emulation requirements for model planes are better met with, so that the quality of products, as well as amateursxe2x80x2 interest therein, are much raised and the sphere for emulation model planes is further developed. 2) As propelling direction adjusting in both longitudinal and transverse directions is possible, the propelling force can be kept stable, thus also stabling the flight of the model plane. 3) As two propellers are used which rotate in opposite directions, the gyro moment can be removed, thus also realizing stable flight. 4) As rubber bands of different kinds can be replaced, a variety of horsepower to weight ratios are available. 5) A rubber band winder and a switch adopted in the present invention make possible to store power, and flight can be easily manipulated. 6) A triangular structure formed by the propeller space locator and the two support bars, provides, together with the various connecting parts of the model plane, a robot driving device of very stable structure. 7) The driving device for a two-propeller model plane according to the present invention is easy and convenient to assemble and disassemble, and simple to maintain and repair.
The above advantages as well as others will be clearly seen in a detailed description below, in connection with the accompanying drawings.